User’s Manual
1.6.8Winbond W83977EF
The W83977EF is an evolving product from Winbond's most popular I/O chip W83877F which integrates the disk drive adapter, serial port (UART), IrDA 1.0 SIR, parallel port, and configurable plug-and-play registers for the whole chip --- plus additional powerful features: ACPI, 8042 keyboard controller with PS/2 mouse support, 14 general purpose I/O ports, full 16-bit address decoding, OnNow keyboard Wake-Up, and OnNow mouse Wake-Up.
The disk drive adapter functions of W83977EF include a floppy disk drive controller compatible with the industry standard 82077/765, data separator, write pre-compensation circuit, decode logic, data rate selection, clock generator, drive interface control logic, and interrupt and DMA logic. The wide range of functions integrated onto the W83977EF greatly reduces the number of components required for interfacing with floppy disk drives. The W83977EF supports four 360K, 720K, 1.2M, 1.44M, or 2.88M disk drives and data transfer rates of 250 Kb/s, 300 Kb/s, 500 Kb/s,1 Mb/s, and 2 Mb/s.
The W83977EF provides two high-speed serial communication ports (UARTs), one of which supports serial Infrared communication. Each UART includes a 16-byte send/receive FIFO, a programmable baud rate generator, complete modem control capability, and a processor interrupt system. Both UARTs provide legacy speed with baud rate up to 115.2k bps and also advanced speed with baud rates of 230k, 460k, or 921k bps which support higher speed modems.
The W83977EF supports one PC-compatible printer port (SPP), Bi-directional Printer port (BPP) and also Enhanced Parallel Port (EPP) and Extended Capabilities Port (ECP). Through the printer port interface pins, also available are: Extension FDD Mode and Extension 2FDD Mode, allowing one or two external floppy disk drives to be connected. The configuration registers support mode selection, function enable/disable, and power down function selection. Furthermore, the configurable PnP features are compatible with the plug-and-play feature demand of Windows 95TM, which makes system resource allocation more efficient than ever.
W83977EF provides functions that comply with ACPI (Advanced Configuration and Power Interface), including support for legacy and ACPI power management through SMI or SCI function pins. W83977EF also has auto power management to reduce power consumption. The keyboard controller is based on 8042 compatible instruction set, with a 2K Byte programmable ROM and a 256-Byte RAM bank. Keyboard BIOS firmware is available with optional AMIKEYTM-2, Phoenix MultiKey/42TM, or customer code.
The W83977EF provides the system designer with a set of flexible I/O control functions through a set of General Purpose I/O ports. These GPIO ports may serve as simple I/O, or may be individually configured to provide a predefined alternate function.
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